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Abstract:

A number of C-FRP molded material sections that are elongated and made
from a carbon fiber reinforced plastic are placed parallel to each other.
The C-FRP molded material sections are insulated from each other by
honeycomb material sections that are made from an insulating and
nonmagnetic material. The C-FRP molded material sections and the
honeycomb material sections are maintained by a glass fiber layer into a
sheet plate shape.

Claims:

1. A magnetic resonance imaging apparatus comprising:a static magnetic
field generating section that generates a static magnetic field in an
imaging space into which a subject is placed;a gradient magnetic field
generating section that generates a gradient magnetic field to add to the
static magnetic field generated by the static magnetic field generating
section;a transmitting section that transmits a radio frequency pulse to
the imaging space;a receiving section that receives a magnetic resonance
signal from the subject;a calculating section that reconstructs an image
based on the magnetic resonance signal from the receiving section;a table
top that supports the subject; anda bed device to move the table top into
the imaging space;wherein the table top comprises:plural conductive and
elongated material sections placed a distance apart to not contact each
other;insulating material sections that are nonmagnetic provided between
the plural conductive and elongated material sections to insulate the
conductive and elongated sections from each other; anda material to hold
the conductive and elongated sections and the insulating material
sections into a plate sheet shape.

2. The magnetic resonance imaging apparatus according to claim 1,wherein
the conductive and elongated material sections are made from carbon fiber
reinforced plastic (C-FRP).

3. The magnetic resonance imaging apparatus according to claim 2,wherein
the insulating material sections are made from a nonmagnetic and
insulating material; andthe conductive and elongated material sections
and insulating material sections are staggered parallel to each other.

4. The magnetic resonance imaging apparatus according to claim 3,wherein a
longitudinal direction of the conductive and elongated material sections
is substantially parallel to a longitudinal direction of the table top or
a cross-direction of the table top.

5. The magnetic resonance imaging apparatus according to claim 3,wherein a
longitudinal direction of the conductive and elongated material sections
is not parallel to either a longitudinal direction of the table top or a
cross-direction of the table top.

6. The magnetic resonance imaging apparatus according to claim 3,wherein a
first group of the conductive and elongated material sections are placed
substantially parallel to a first direction; anda second group of the
conductive and elongated material sections are placed substantially
parallel to a second direction different from the first direction.

7. The magnetic resonance imaging apparatus according to claim 6,wherein
the first direction is substantially parallel to the longitudinal
direction of the table top; andthe second direction is substantially
parallel to the cross-direction of the table top.

8. The magnetic resonance imaging apparatus according to claim 6,wherein
the first direction and the second direction are not parallel to the
longitudinal direction of the table top and are not parallel to the
cross-direction of the table top.

9. The magnetic resonance imaging apparatus according to claim 1,wherein
the insulating material sections are made from carbon fiber reinforced
plastic (C-FRP).

10. The magnetic resonance imaging apparatus according to claim 1,wherein
the insulating material sections have a structure of a honeycomb.

11. The magnetic resonance imaging apparatus according to claim 10,wherein
the honeycomb shape of the insulating material sections is placed in the
vertical direction of the table top.

12. A bed device for a magnetic resonance imaging apparatus comprising:a
table top comprising:plural conductive and elongated material sections
placed a distance apart to not contact each other;insulating material
sections that are nonmagnetic provided between the plural conductive and
elongated sections to insulate the conductive and elongated sections from
each other; anda material to hold the conductive and elongated sections
and the insulating material sections into a plate sheet shape.

13. A bed device for a magnetic resonance imaging apparatus according to
claim 12,wherein the elongated material sections are made from carbon
fiber reinforced plastic (C-FRP).

14. A bed device for a magnetic resonance imaging apparatus according to
claim 13,wherein the insulating material sections are made from a
nonmagnetic and insulating material; andthe conductive and elongated
material sections and insulating material sections are staggered parallel
to each other.

15. A bed device for a magnetic resonance imaging apparatus according to
claim 14,wherein a longitudinal direction of the conductive and elongated
material sections are substantially parallel to a longitudinal direction
of the table top or a cross-direction of the table top.

16. A bed device for a magnetic resonance imaging apparatus according to
claim 14,wherein a longitudinal direction of the conductive and elongated
material sections is not parallel to either a longitudinal direction of
the table top or a cross-direction of the table top.

17. A bed device for a magnetic resonance imaging apparatus according to
claim 14,wherein a first group of the conductive and elongated material
sections are placed substantially parallel to a first direction; anda
second group of the conductive and elongated material sections are placed
substantially parallel to a second direction different from the first
direction.

18. A bed device for a magnetic resonance imaging apparatus according to
claim 17,wherein the first direction is substantially parallel to the
longitudinal direction of the table top; andthe second direction is
substantially parallel to the cross-direction of the table top.

19. A bed device for a magnetic resonance imaging apparatus according to
claim 17,wherein the first direction and the second direction are not
parallel to the longitudinal direction of the table top and are not
parallel to the cross-direction of the table top.

20. A bed device for a magnetic resonance imaging apparatus according to
claim 12,wherein the insulating material sections are made from carbon
fiber reinforced plastic (C-FRP).

21. A bed device for a magnetic resonance imaging apparatus according to
claim 12,wherein the insulating material sections have a structure of a
honeycomb.

22. A bed device for a magnetic resonance imaging apparatus according to
claim 21,wherein the honeycomb shape of the insulating material sections
are placed in the vertical direction of the table top.

23. A table top of a bed device for a magnetic resonance imaging apparatus
comprising:plural conductive and elongated material sections placed a
distance apart to not contact each other;insulating material sections
that are nonmagnetic provided between the plural conductive and elongated
material sections to insulate the conductive and elongated material
sections from each other; anda material to hold the conductive and
elongated sections and the insulating material sections into a plate
sheet shape.

24. A table top of a bed device for a magnetic resonance imaging apparatus
according to claim 23,wherein the conductive and elongated material
sections are made from carbon fiber reinforced plastic (C-FRP).

25. A table top of a bed device for a magnetic resonance imaging apparatus
according to claim 24,wherein the insulating material sections are made
from a nonmagnetic and insulating material; andthe conductive and
elongated material sections and insulated material sections are staggered
parallel to each other.

26. A table top of a bed device for a magnetic resonance imaging apparatus
according to claim 25,wherein a longitudinal direction of the conductive
and elongated material sections are substantially parallel to a
longitudinal direction of the table top or a cross-direction of the table
top.

27. A table top of a bed device for a magnetic resonance imaging apparatus
according to claim 25,wherein a longitudinal direction of the conductive
and elongated material sections are not parallel to either a longitudinal
direction of the table top or a cross-direction of the table top.

28. A table top of a bed device for a magnetic resonance imaging apparatus
according to claim 25,wherein a first group of the conductive and
elongated material sections are placed substantially parallel to a first
direction; anda second group of the conductive and elongated material
sections are placed substantially parallel to a second direction
different from the first direction.

29. A table top of a bed device for a magnetic resonance imaging apparatus
according to claim 28,wherein the first direction is substantially
parallel to the longitudinal direction of the table top; andthe second
direction is substantially parallel to the cross-direction of the table
top.

30. A table top of a bed device for a magnetic resonance imaging apparatus
according to claim 28,wherein the first direction and the second
direction are not parallel to the longitudinal direction of the table top
and are not parallel to the cross-direction of the table top.

31. A table top of a bed device for a magnetic resonance imaging apparatus
according to claim 23,wherein the insulating material sections are made
from carbon fiber reinforced plastic (C-FRP).

32. A table top of a bed device for a magnetic resonance imaging apparatus
according to claim 23,wherein the insulating material sections have a
structure of a honeycomb.

33. A table top of a bed device for a magnetic resonance imaging apparatus
according to claim 32,wherein the honeycomb shape of the insulating
material sections is placed in the vertical direction of the table top.

Description:

CROSS-REFERENCE TO PRIORITY APPLICATIONS

[0001]The present application is based on and claims priority to Japanese
Patent Application No. P2008-285569 filed on Nov. 6, 2008, the entire
contents of which is hereby incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002]1. Field of the Invention

[0003]The present invention relates to magnetic resonance imaging
apparatuses, and more particularly to bed devices to feed subjects into
imaging spaces and table tops of the bed devices.

[0004]2. Description of the Related Art

[0005]A table top to feed a subject into an imaging space for example of a
MRI apparatus is required to be nonmagnetic and nonconductive to prevent
observing a magnetic resonance phenomenon in the subject. Therefore, the
table top is conventionally composed of a wood material. Recently, to be
craft friendly or for weight saving, it has become common for the table
top to be composed of glass fiber reinforced plastic (G-FRP) (see Jpn.
Pat. App. KOKAI Publication No. 2008-006200).

[0006]However, recently it is necessary for an MRI apparatus to scan a
wide range with one search for a screening scan etc. Therefore, a range
of movement for the bed device has widened. A wider range of the bed
device improves a maximum overhang length from the bed device to the
table top. Meanwhile, a magnetic gantry that generates static magnetic
control that tends to shorten an axis and consequently the length of a
projecting part of the table top in the direction of backward of the
magnetic gantry (opposite side of the bed device) has had to be
lengthened. Therefore, the table top is being required to support a
greater load.

[0007]From the above facts, sometimes wood and G-FRP do not provide all
the properties currently being required from the bed device. In addition,
although G-FRP gives a certain level of strength of the bed device by
heightening to a filling fraction of a glass fiber in the G-FRP, the more
the filling fraction of the glass fiber in G-FRP is increased, the
greater a strain in molding the G-FRP and the heavier the G-FRP.

SUMMARY OF THE INVENTION

[0008]In view of such circumstances, an object of the present invention is
to provide a table top that is light and easy to mold and with high
strength.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009]The accompanying drawing, which are incorporated in and constitute a
part of the specification, illustrate embodiments of the invention, and
together with the general description given above and the detailed
description of the embodiments given below, serve to explain the
principles of the invention, in which:

[0010]FIG. 1 is a block diagram showing a structure of an MRI apparatus
according to an embodiment of the invention;

[0011]FIG. 2 is a perspective view showing an appearance of an MRI
apparatus that has a table top according to the embodiment of FIG. 1;

[0012]FIG. 3 is a perspective view showing a structure of a part of a
table top according to the embodiment of FIG. 1;

[0013]FIG. 4 is a cross-section showing a structure of a table top for an
MRI apparatus according to an embodiment of the table top;

[0014]FIG. 5 is a plan view showing a structure of a table top for an MRI
apparatus according to an embodiment of the table top;

[0015]FIG. 6 is a plan view showing a structure of a table top for an MRI
apparatus according to an embodiment of the table top;

[0016]FIG. 7 is a plan view showing a structure of a table top for an MRI
apparatus according to an embodiment of the table top;

[0017]FIG. 8 is a plan view showing a structure of a table top for an MRI
apparatus according to an embodiment of the table top;

[0018]FIG. 9 is a cross section showing a structure of a table top for an
MRI apparatus according to another embodiment of the table top;

[0019]FIG. 10 is a plan view showing a structure of a table top for an MRI
apparatus according to another embodiment of the table top.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0020]A magnetic resonance imaging apparatus (an MRI apparatus) according
to an embodiment of the invention will now be explained with reference to
the figures. At first, units of a MRI apparatus 100 according to this
embodiment will be explained. FIG. 1 is a block diagram showing a
structure of an MRI apparatus 100 according to this embodiment.

[0021]The MRI apparatus 1 includes an imaging section 1, a bed device 2,
an operating section 3, and a system control section 4. The imaging
section 1 collects a magnetic resonance signal (an MR signal) from a
subject P, and performs an arithmetic operation based on the collected MR
signal. The bed device 2 sets the subject P at an imaging position of the
imaging section 1. The operating section 3 accepts an operation by an
operator to control the imaging section 1 and the bed device 2. The
system control section 4 controls the imaging section 1 and the bed
device 2 based on a signal from the operating section 3.

[0022]The imaging section 1 includes a gantry 11, a gantry control section
12, and a signal processing section 13.

[0023]The gantry 11 includes a magnet 111, a gradient coil 112, an RF coil
113, and a receiving coil 114. A cylindrical imaging space 115 where the
subject P is imaged is formed in the gantry 11. The magnet 111, the
gradient coil 112, and the RF coil 113 are arranged such that this
imaging space 115 serves as an axis. The magnet 111 generates a static
magnetic field in the imaging space 115. For this magnet 111, a
superconducting magnet can be utilized, for example. When using a
superconducting magnet as the magnet 111, a non-illustrated static power
supply is provided. The gradient coil 112 is arranged on an inner
circumference of the magnet 111.

[0024]The gradient coil 112 generates a gradient magnetic field in the
imaging space 115 when a power is supplied from a non-illustrated
gradient power supply. The RF coil 113 is arranged on an inner
circumference of the gradient coil 112. When a radio frequency signal is
supplied from the gantry control section 12, the imaging space 115 is
transmitted with a radio frequency pulse to excite a hydrogen atomic
nucleus in the subject P by the RF coil 113. The receiving coil 114 is
arranged on the bed device 2, and is fed into the imaging space 115 by
the bed device 2, at the time of imaging. The receiving coil 114 converts
the MR signal emitted as an electromagnetic wave from the subject P into
an electric signal state, and outputs the converted MR signal to the
gantry control section 12.

[0025]The gantry control section 12 includes a gradient magnetic field
control section 121, a static magnetic field control section 122, and an
RF transmitting/receiving section 123.

[0026]The gradient magnetic field control section 121 controls the
gradient power supply. The static magnetic field control section 122
controls the static power supply. The RF transmitting/receiving section
123 supplies an RF signal to the RF coil 113. The RF
transmitting/receiving section 123 performs reception processing with
respect to the MR signals output from the RF coil 113 and the receiving
coil 114, and then outputs the processed signals to the signal processing
section 13. Further, the RF transmitting/receiving section 123 performs
sequence control to carry out generation of a gradient magnetic field,
transmission of the RF signal, and reception of the MR signal in
accordance with predetermined sequences.

[0027]The signal processing section 13 includes a calculating section 131
and a display section 132. The calculating section 131 reconstructs an
image from the MR signal supplied from the RF transmitting/receiving
section 123. The display section 132 displays the image reconstructed by
the calculating section 131. As the display section 132, a CRT (a
cathode-ray tube) can be utilized for example.

[0029]The bed movement section 21 includes a horizontal movement section
211 and a bed support section 212. The horizontal movement section 211
includes a table top 2111 and a middle frame 2112. The subject P is
mounted on a top surface of the table top 2111. Furthermore, the
receiving coil 114 is arranged over the subject P. The middle frame 2112
supports the table top 2111 to be movable in a horizontal direction. The
bed support section 212 supports the horizontal movement section 211 to
be movable in a vertical direction.

[0030]The mechanism section 22 includes a horizontal movement mechanism
section 221, a position detector 222, and a vertical movement mechanism
section 223. The horizontal movement section 211 horizontally moves the
table top 2111. The position detector 222 detects a position of the table
top 2111. The vertical movement mechanism section 223 vertically moves
the bed support section 212.

[0031]The operating section 3 includes a non-illustrated inputting device,
for example a keyboard, and a display device. The operating section 3 is
used by an operator to input an operation of the bed device 2, e.g. to
input a setting for the subject P mounted on the table top 2111 to an
appropriate position in the imaging space 115. Moreover, the operating
section 3 can be arranged on the gantry 11 to enable an operation near
the subject P when moving the subject P. The operating section 3 supplies
a signal indicative of contents of an operation input by the operator to
the system control section 4.

[0032]The system control section 4 includes a CPU, a storage circuit, and
other elements. The system control section 4 performs overall control
with respect to each section in the MRI apparatus 100 based on an input
signal from the operating section 3.

[0033]The table top 2111 of the MRI apparatus will now be explained.

[0034]FIG. 2 is a perspective view showing an appearance of an MRI 100
apparatus that has a table top 2111 according to each embodiment of the
invention.

[0035]The bed device 2 feeds the subject P that is placed on the table top
2111 into the imaging space 115 by the horizontal movement mechanism
section 221 (shown in FIG. 1) moving the table top 2111.

[0036]A length of the table top 2111 in the direction the table top 2111
is moved to feed the subject P into the imaging space 115 (the
longitudinal direction) is much longer than a length of the table top
2111 at right angles to that moving direction (the cross or width
direction).

[0037]The following discussion refers to the longitudinal direction of the
table top 2111 as the table top longitudinal direction and refers to the
direction that lies at right angles to the table top 2111 longitudinal
direction as a table top cross or width direction.

[0038]FIG. 3 is a perspective view showing a structure of a part of a
table top 2111 in FIG. 2.

[0039]As shown in FIG. 3, the table top 2111 includes a plate section
2111a, and wall sections 2111b, 2111c, 2111d. The plate section 2111a
makes up almost all the extent of the table top 2111. The wall sections
2111b and 2111c are formed at both ends of the plate section 2111a to
extend in the longitudinal direction.

[0040]The wall section 2111d is formed at the end of the plate section
2111a to extend in the table top width direction. The wall sections
2111b, 2111c and 2111d can hold a cushion 2113 (see FIG. 2) and the
receiving coil 114 (see FIG. 1) and so on. As shown in FIG. 3, the wall
section 2111d includes a handle 2114.

[0041]Detailed embodiments of the structure of the table top 2111 will now
be explained.

[0042]FIG. 4 is a cross-section showing a structure of a table top
21111 according to an embodiment of the invention, along the width
direction. Although FIG. 4 shows the outline of the relationship of the
position of components of the table top 21111, the sizes and
measurements of each component can be varied.

[0043]As shown in FIG. 4, the table top 21111 according to the
embodiment includes a number of C-FRP molded material sections 51, a
number of honeycomb material sections 52, a glass fiber layer 53, and an
outer shell 54.

[0044]FIG. 5 is an overhead plan view showing the structure of a table top
21111 according to the embodiment.

[0045]As shown in FIG. 5, C-FRP molded material sections 51 are made of a
longitudinal material of molded carbon fiber reinforced plastic that is
long and narrow. The length of the longitudinal direction of the C-FRP
molded material sections 51 is a little shorter than the total length of
the table top longitudinal direction of the table top 21111. The
width of the C-FRP molded material sections 51 is sufficiently smaller
than the length of the table top 21111 in the width direction. A
number of the C-FRP molded material sections 51 are placed so the
longitudinal direction of them extends along the shape of the table top
in the longitudinal direction. Thus, a number of C-FRP molded material
sections 51 are placed parallel to each other.

[0046]The honeycomb material sections 52 are nonmagnetic and
nonconductive, and are molded to be long and narrow and to have a
honeycomb structure. For example, glass fiber reinforced plastic, paper,
and resin are used as a material of the honeycomb material sections 52.
Wood can be used as an insulation material that insulates a number of
C-FRP molded material sections 51 instead of the honeycomb material
sections 52. The length of the honeycomb material sections 52 are
sufficiently smaller than the length of the table top 21111 in the
longitudinal direction. The width of the honeycomb material sections 52
is sufficiently smaller than the length of the table top 21111 in
the width direction. As shown in FIG. 5, a number of honeycomb material
sections 52 are placed in the plate section 2111a and the wall sections
2111b, 2111c shown in FIG. 3.

[0047]In addition, as shown in FIG. 4, the C-FRP molded material sections
51 and the honeycomb material sections 52 are placed in the plate section
2111a and the wall sections 2111b, 2111c of FIG. 3. The honeycomb
material sections 52 are placed exposing a honeycomb shape of the
honeycomb material 52 in the vertical direction of a plate of the table
top 2111. Thus, the strength of the table top 2111 against a load coming
from the vertical direction of the plate is increased.

[0048]The glass fiber layer 53 is formed of glass fiber in a cloth shape.
As shown in FIG. 4, the glass fiber layer 53 is formed around the C-FRP
molded material sections 51 and the honeycomb material sections 52, and
keeps the C-FRP molded material sections 51 and the honeycomb material
sections 52 in the plate state of the arrangement of FIG. 4. The glass
fiber layer 53 can be formed one time around the C-FRP molded material
sections 51 and the honeycomb material sections 52 or can be formed many
times around the C-FRP molded material sections 51 and the honeycomb
material sections 52.

[0049]The outer shell 54 is made from a nonmagnetic and nonconductive
material, and covers the C-FRP molded material sections 51, the honeycomb
material sections 52, and the glass fiber layer 53. Thus, a core
structure of this embodiment is an arrangement in which a number of the
C-FRP molded material sections 51 and a number of the honeycomb material
sections 52 are alternately arranged in the table top 21111. The
core structure prevents the table top 2111 from transforming or twisting
about the table top longitudinal direction. However, because the strength
of the C-FRP molded material sections 51 is higher than the strength of
the honeycomb material sections 52, the prevention of the previous
transformation depends mainly on the C-FRP molded material sections 51.

[0050]As shown in FIG. 4, a cross-section area of the C-FRP molded
material sections 51 and a cross-section area of the honeycomb material
sections 52 are nearly the same. Therefore, the ratio of the
cross-section area of the C-FRP molded material sections 51 in the whole
cross-section of the core is about 1/2. The strength of the C-FRP
material depends on the filling ratio of carbon, and the strength of the
C-FRP material is generally about 5 or 6 times higher than a G-FRP
material. Therefore, the strength of the table top 21111 in the case
that a number of C-FRP molded material sections 51 are partially placed
in the table top 21111 can be increased greater than in the case of
the table top being molded using the G-FRP. And because the specific
gravity of C-FRP is lower than of G-FRP, and the specific gravity of the
honeycomb material sections 52 is lower than G-FRP, when the table top
21111 is molded by using the honeycomb material sections 52 that
have high air tightness, the table top 21111 can be made
lightweight. Furthermore, the C-FRP molded sections 51 individually have
a simple shape, and their cross-section area is small. Thus, the C-FRP
molded material sections 51 are molded relatively easily with a simple
processing.

[0051]In addition, the honeycomb material sections 52 do not have the
strength of the C-FRP molded material sections 51, but still assist in
prevention of transformation of the table top 21111. Furthermore,
when the table top 21111 is shaped, a resin is poured into the
inside of the glass fiber layer 53.

[0052]The honeycomb material sections 52 also have a function of a spacer
to prevent too much resin from running into the inside of the glass fiber
layer 53 and making the table top 21111 heavier than necessary.

[0053]Also, because the C-FRP material is conductive, an induced electric
current generates a magnetic field, and the magnetic field could effect
the observation of the magnetic resonance phenomenon. However, the
honeycomb material sections 52 insulate the C-FRP molded material
sections 51 from each other. Therefore, the C-FRP molded material
sections 51 do not significantly affect the observation of the magnetic
resonance phenomenon. A number of the C-FRP molded material sections 51
placed in the table top 21111 is variable while still maintaining
the size of the table top 2111, for example by making the cross-section
area of the C-FRP molded material sections 51 smaller and increasing the
number of the C-FRP sections within the table top 2111. Because the
smaller the cross-section area of the electrical conducting material the
lower the induced current is, the induced current that is generated on
each C-FRP molded material section 51 can be reduced. Therefore, the
magnetic field that the induced current generates and any adverse effect
of observation of the magnetic resonance phenomenon can be minimized.

[0054]In addition, as shown in FIG. 5, the C-FRP molded material sections
51 are placed so their longitudinal direction extends along the shape of
the table top 21111 in the longitudinal direction, and the honeycomb
material sections 52 are placed so their longitudinal direction also
extends along the shape of the table top in the longitudinal direction,
and they are placed between the C-FRP molded material sections 51. But
such an arrangement of the C-FRP molded material sections 51 and the
honeycomb material section 52 is non-limiting.

[0055]For example, as shown in FIG. 6, showing a table top 21112 as a
modification of the above-discussed embodiment, the C-FRP molded material
sections 51 can be placed so their longitudinal direction extends along
the shape of the table top 21112 in a width direction, and the
honeycomb material sections 52 can be placed so their longitudinal
direction extends along the shape of the C-FRP molded material sections
51 in the width direction.

[0056]As another example shown in FIG. 7 showing a table top 21113 as
another modification of the above-discussed embodiment, the C-FRP molded
material sections 51 can be placed so their longitudinal direction does
not extend along the shape of the table top in the longitudinal or width
direction, but instead at an angle to both the longitudinal and width
directions, and the honeycomb material sections 52 can be placed so their
longitudinal direction also does not extend along the shape of the table
top in the longitudinal or width direction, but instead at an angle to
both the longitudinal and width directions, and placed between the C-FRP
molded material sections 51. In particular, the arrangement shown in FIG.
7 can increase the strength of the table top 21113 about the
longitudinal direction.

[0057]Furthermore, the C-FRP molded material sections 51 on a table top
21114 according to another modification of the above discussed
embodiment can be divided into plural separate areas, as shown in FIG. 8.
The melting resin can be poured into the space between the C-FRP molded
material sections 51 that are divided and the C-FRP molded material
sections 51 can be insulated from each other by placing the honeycomb
material sections 52 between the C-FRP molded material sections 51.

[0058]The divided C-FRP molded material sections 51 can be molded easier
in this embodiment of FIG. 8 and the divided C-FRP molded material
sections 51 can lighten the table top 2111 more than if the C-FRP molded
material sections 51 are not divided.

[0059]FIG. 9 is a cross-section showing a structure of a table top
21115 according to another embodiment of the invention. And in FIG.
9, the same parts of the embodiment of FIG. 4 are indicated by the same
reference indicators, and their explanation in detail will be skipped.
However, FIG. 9 shows the outline of the relationship of the position of
components of the table top 21115 of this embodiment, although the
dimensions and spacing of each component can be varied in practice.

[0060]As shown in FIG. 9, the table top 21115 according to this
embodiment includes the glass fiber layer 53, the outer shell 54, a
number of C-FRP pultrusion productions 55, and a number of G-FRP material
sections 56. That is to say, in this embodiment, the table top 21115
includes the C-FRP pultrusion productions 55 and the G-FRP material
sections 56 instead of the C-FRP molded material sections 51 and the
honeycomb material sections 52 of the embodiments of FIGS. 4-8.

[0061]The C-FRP pultrusion productions 55 are made of a longitudinal
material molded to be long and narrow. The length of the C-FRP pultrusion
productions 55 in the longitudinal direction is a little shorter than the
length of the table top 2112 in the longitudinal direction, similar to
the embodiment of FIGS. 4-8. The width of the C-FRP pultrusion
productions 55 is sufficiently smaller than the length of the table top
21115 in the width direction. A number of the C-FRP pultrusion
productions 55 are placed so their longitudinal direction extends along
the shape of the table top longitudinal direction, and with a spacing
between each other. Thus, a number of C-FRP pultrusion productions 55 are
placed parallel to each other between the G-FRP material sections 56.

[0062]The G-FRP material sections 56 are of a longitudinal material molded
to be long and narrow. The width of the G-FRP material sections 56 is
sufficiently smaller than the length of the table top in the longitudinal
direction. A number of the G-FRP material sections 56 are placed so their
longitudinal direction extends along the shape of the table top in the
longitudinal direction, and are placed between the C-FRP pultrusion
productions 55.

[0063]The glass fiber layer 53 is formed around the C-FRP pultrusion
productions 55 and the G-FRP material sections 56, and keeps the C-FRP
pultrusion productions 55 and the G-FRP material sections 56 in the plate
state of the arrangement of FIG. 9. The outer shell 54 covers the C-FRP
pultrusion productions 55, the G-FRP material sections 56, and the glass
fiber layer 53.

[0064]Thus, a core structure of this embodiment is an arrangement in which
a number of the C-FRP pultrusion productions 55 and a number of the G-FRP
material sections 56 are alternately arranged in the table top
21115. The core structure prevents the table top 21115 from
transforming or twisting about the table top longitudinal direction.
However, because the strength of the C-FRP pultrusion productions 55 is
higher than the strength of the G-FRP material sections 56, the strength
of the core according to this embodiment can be higher than a core formed
by only the G-FRP material sections 56 in which the cross-section area is
the same. And utilizing the C-FRP pultrusion productions 55 can provide
sufficient strength by not requiring increasing the filling ratio of
glass fiber. The G-FRP material sections 56 is not needed to provide high
mechanical strength, and therefore it is not necessary to increase a
ratio of the glass fiber. Furthermore, the C-FRP pultrusion productions
55 and the G-FRP material sections 56 individually have a simple shape,
and the C-FRP pultrusion productions 55 and the G-FRP material sections
56 can be molded relatively easily with a simple processing.

[0065]The G-FRP material sections 56 are nonmagnetic and nonconductive.
The G-FRP material sections 56 have a function that increase the strength
of the core, and a function that insulates the C-FRP pultrusion
productions 55 from each other. Because a number of the C-FRP pultrusion
productions 55 are placed in the table top 21115, the cross-section
area of the C-FRP pultrusion productions 55 can be made smaller
regardless of the measurement of the table top 21115, compared with
not including the C-FRP pultrusion productions 55. Because the C-FRP
pultrusion productions 55 are insulated by the G-FRP material sections
56, the induced current that is generated on each C-FRP pultrusion
productions 55 is low and the magnetic field that this induced current
generates is low. Therefore, any adverse effects of observation of
magnetic resonance phenomenon can be minimized.

[0066]In the above discussed embodiments, as shown for example in FIGS. 5
and 9, the C-FRP molded material sections 51 and the honeycomb material
sections 52 or the C-FRP pultrusion productions 55 and the G-FRP material
sections 56 of the table top 2111 are placed with their longitudinal
direction extending in the longitudinal direction of the table top 2111,
or as shown in FIG. 6 and FIG. 7, are placed with their longitudinal
directions extending in a different direction than the longitudinal
direction of the table top 2111. In fact, in the above-discussed
embodiments, the C-FRP molded material sections 51 and the honeycomb
material sections 52 or the C-FRP pultrusion productions 55 and the G-FRP
material sections 56 are placed with their longitudinal directions being
in the same direction to each other.

[0067]In a further embodiment, the arrangement of the C-FRP molded
material sections 51 and the honeycomb material sections 52 or the C-FRP
pultrusion productions 55 and the G-FRP material sections 56 is different
from the arrangement in the above-discussed embodiments, as explained
below.

[0068]FIG. 10 is an overhead plan view showing a structure of a table top
21116 according to another embodiment of the invention.

[0069]As shown in FIG. 10, in the table top 21116, some of the C-FRP
molded material sections 51 are placed so their longitudinal direction
extends along the shape of the longitudinal direction of the table top
21116, and with honeycomb material sections 52 between them, and
some of the C-FRP molded material sections 51 are placed so their
longitudinal direction extends along the shape of the table top
21116 in its width direction, with honeycomb material sections 52
between them.

[0071]With this structure in FIG. 10, the load in every direction against
the table top 21116 can be compensated for, and the strength of the
table top 2111 can be increased. In addition, in this embodiment, as
shown in FIG. 10, the C-FRP molded material sections 51 that are placed
along the longitudinal direction of the table top 21116 are divided
into several separate areas, and thereby the melting resin can be poured
into the space between divided C-FRP molded material sections 51, and the
honeycomb material sections 52 can be placed in the space between divided
C-FRP molded material sections 51 to insulate C-FRP molded material
sections 51 from each other. The C-FRP molded material sections 51 could
alternatively be placed in the table top 21116 without dividing the
C-FRP molded material sections 51.

[0072]Each of the above-discussed embodiments can be modified in various
ways such as the following.

[0073]In the embodiment of FIGS. 4-8, a solid material can be used instead
of the honeycomb material sections 52. However, because the honeycomb
material sections 52 can maintain strength and provide a weight saving,
it is preferred that the honeycomb material sections 52 are used:

[0074]Also in the embodiment of FIGS. 4-8, the cross-section shape of the
C-FRP molded material sections 51 and the honeycomb material sections 52
can be various shapes, for example a circular or an oval figure, and the
cross-section shape of the C-FRP molded material sections 51 can be
different from the cross-section shape of the honeycomb material sections
52.

[0075]In the embodiment of FIG. 9, the cross-section shape of the C-FRP
pultrusion productions 55 and the G-FRP material sections 56 can be
various shapes, for example an oval figure or a square-shaped, and the
cross-section shape of the C-FRP pultrusion productions 55 can be
different from the cross-section shape of the G-FRP material sections 56.

[0076]In the embodiments of FIGS. 4-9, the C-FRP molded material sections
51 and the honeycomb material sections 52, or the C-FRP pultrusion
productions 55 and the G-FRP molded material sections 56, can be molded
with a sandwich structure plate material matching the shape of the plate
sections 2111a and the wall section 2111b, 2111c and 2111d, and the outer
shell can be formed by a glass fiber layer.

[0077]In the embodiments of FIGS. 4-9, the melting resin can be poured
into a gap between the C-FRP molded material sections 51 or the C-FRP
pultrusion productions 55 and the resin can be set for insulating about
the C-FRP molded material sections 51 and the C-FRP pultrusion
productions 55. That is to say, the number of the insulating material
sections can be reduced and the resin can perform their insulating
function. In the embodiments of FIGS. 4-9, the C-FRP molded material
sections 51 or the C-FRP pultrusion productions 55 can also be placed in
the thickness direction.

[0078]The outline of the table top 2111 can also be changed in shape. For
example, the angle of gradient of the wall sections 2111b, 2111c can be
changed. And part or all of the wall sections 2111b, 2111c and 2111d can
be eliminated.

[0079]Additional advantages and modifications will readily occur to those
skilled in the art. Therefore, the invention in its broader aspects is
not limited to the specific details and representative embodiments shown
and described herein. Accordingly, various modifications may be made
without departing from the spirit or the general inventive concept as
defined by the appended claims and their equivalents. For example, some
component of all components that are shown in each embodiment can be
omitted. Furthermore, components of the different embodiments can be
combined.

Patent applications by KABUSHIKI KAISHA TOSHIBA

Patent applications by TOSHIBA MEDICAL SYSTEMS CORPORATION

Patent applications in class With means for positioning patient or body part

Patent applications in all subclasses With means for positioning patient or body part